Dispensers have been developed for emitting a fluid into ambient surroundings. For example, spray or misting devices are often used to dispense a variety of fluids, such as insecticides/pest repellants, cleaning solutions, fertilizers, etc. Such devices may be manually operable, motor-operated, or a combination of the two. Fluid dispensing devices typically use a pressurized source of fluid. Often, the fluid is pressurized by an apparatus, such as a pump, disposed in the device.
Dispensers that are particularly adapted for use in outdoor applications are typically used to spray or otherwise eject amounts of fluid, often over a large area. Because it is usually the case that a fluid must be selectively applied to some surfaces and not others, there is a need to control emission characteristics, such as flow magnitude and distribution, so that unintended overspray is minimized. Compounding this issue is the effect of moving air (i.e., wind) on the emission flow, which can undesirably alter the desired distribution, and can result in deposition of fluid on one or more surfaces that are not intended to receive fluid. Alternatively, one may wish to use wind to assist in the dispersion of fluid. Thus, for example, one may spray upwind and allow the dispersed material to drift onto surfaces.
The need to control emission characteristics carefully has, in the past, led to the use of complex and expensive components. This was especially the case when liquids were to be dispensed in residential areas, where particular care had to be taken to prevent contamination of on-site and off-site areas. Accordingly, particularly in the case where relatively large amounts of liquids were to be dispensed in an outdoor setting, such dispensing devices have been complex and difficult to use, and expensive to purchase and operate.